1. Field of the Invention
The present invention relates generally to an optical storage apparatus, a method for storage and regeneration from an optical storage medium and a method for recording on the optical storage medium, which record and regenerate information by use of laser beams, and more particularly, to an optical storage apparatus, a method for storage and regeneration from an optical storage medium and a method of recording on the optical storage medium, which optimize recording and regeneration conditions from retry operations in the case where errors occur in recording and regeneration operations of an optical storage medium including an MSR medium for recording and regenerating data with a smaller density than a beam diameter.
2. Description of the Related Arts
In a process of a conventional optical recording and regeneration apparatus for executing a read command from a host, when a plurality of sectors are processed by one (1) read command for normal termination, a retry setting is learned at the time of termination to change default conditions. In this case, a target of the learning is a retry setting when the last sector is processed. In other words, a read learning is performed when the read command is completed; a counter is controlled by the last successful mode; a regeneration power and a regeneration magnetic field are learned; and regeneration conditions are optimized.
FIGS. 1A, 1B and 1C are flowcharts of conventional a read command process which consists of following process procedures.
Step S1: A read command received from a host is decoded and a read operation is executed.
Step S2: It is checked whether the read operation failed or not, and if failed, the process proceeds to step S3; and otherwise, the process proceeds to step S6.
Step S3: It is checked whether the number of the read retry exceeds a predetermined number or not. If the number does not exceed the predetermined number, the process proceeds to step S4; and otherwise, the process proceeds to step S5.
Step S4: The number of the read retry is updated; a read condition is changed; and the process returns to the read execution in step S1 to execute a retry read. For changing the read condition, the change is performed by alternatively adding sequentially increasing positive and negative offsets to a default value of read power, and if the change still does not succeed, the change is performed by alternatively adding sequentially increasing positive and negative offsets to a default value of a regeneration magnetic field.
Step S5: This procedure is the case where the predetermined number of the retry is exceeded resulting in retry out, and an error report is issued to higher order as a defective sector operation.
Step S6: This procedure is the case where the retry succeeds, and it is checked whether the last successful retry mode has contents for changing read power or not. If the retry mode has contents for changing the read power, the process proceeds to step S7; and otherwise, the process proceeds to step S13 of FIG. 1B.
Step S7: It is checked whether, at the time of the successful retry, a read power setting is power up or not. If the setting is power up, the process proceeds to step S8; and otherwise, the process proceeds to step S9.
Step S8: A regeneration power learning counter is updated.
Step S9: It is checked whether, at the time of the successful retry, a read power setting is power down or not. If the setting is power down, the process proceeds to step S10; and otherwise, the process proceeds to step S11.
Step S10: A regeneration power learning counter is updated.
Step S11: It is checked whether the counter exceeds a threshold or not. If exceeding, the process proceeds to step S12: and otherwise, the process is terminated.
Step S12: This procedure is the case that the counter exceeds a threshold, and by learning the read power which is a regeneration condition of the last retry process, a default or previous regeneration condition is changed to the optimized condition determined by the learning. For example, if the regeneration condition of the last retry process is to up the read power, the default read power is increased by predefined value.
Step S13: It is checked whether a regeneration magnetic field of the last successful retry mode has contents which change a setting or not. If the regeneration magnetic field has contents which change a setting, the process proceeds to step S14; and otherwise, the process is terminated.
Step S14: It is checked whether, at the time of the successful retry, a regeneration magnetic field setting is up or not. If the setting is up, the process proceeds to step S15; and otherwise, the process proceeds to step S16.
Step S15: A regeneration magnetic field learning counter is updated.
Step S16: It is checked whether, at the time of the successful retry, a regeneration magnetic field setting is down or not. If the setting is down, the process proceeds to step S17; and otherwise, the process proceeds to step S18.
Step S17: A regeneration magnetic field learning counter is updated.
Step S18: It is checked whether the counter exceeds a threshold or not. If exceeding, the process proceeds to step S19; and otherwise, the process is terminated.
Step S19: This procedure is the case that the counter exceeds a threshold, and by learning the regeneration magnetic field which is a regeneration condition of the last retry process, a default or previous regeneration condition is changed to the optimized condition determined by the learning. For example, if the regeneration condition of the last retry process is to down the regeneration magnetic field, the default regeneration magnetic field is decreased by predefined value.
On the other hand, in a process of a conventional optical storage and regeneration apparatus for executing a write command, an erase, a write and a verify read are executed as processes for one (1) write command, and if operations are normally terminated by executing the write or the verify read, the write power learning and the read learning (regeneration power, regeneration magnetic field learning) with the write verify are performed as the learning for the write command when execution of the write command is completed. For the read learning with the write verify and the read learning with the read command of FIG. 1A, although learned parameters are the same regeneration power and regeneration magnetic field, the learning is executed at different timings.
FIG. 2 is a flowchart of a conventional write command process which consists of following process procedures.
Step S1: An erase operation is executed for a write target sector based on a write command issued from a host.
Step S2: A write operation is executed for the target sector after the erase based on the write command.
Step S3: A verify operation is executed for regenerating and verifying data from the target sector after the write operation.
Step S4: It is checked whether a verify-failed sector exists or not, and if the failed sector exists, the process proceeds to step S5, and otherwise, the process proceeds to step S9.
Step S5: It is checked whether the verify retry reaches the predetermined number resulting in retry-out or not. If the verify retry is not retry-out, the process proceeds to step S8; and if the verify retry is retry-out, the process proceeds to step S6.
Step S6: It is checked whether the write retry reaches the predetermined number to be retry-out or not. If the write retry is not retry-out, the process proceeds to step S11; and if the verify retry is retry-out, the process proceeds to step S7.
Step S7: This procedure is the case where both of the verify retry and the write retry is retry-out, and after determining as a defective sector, a replacement process is executed and the process is terminated.
Step S8: This procedure is the case where the verify retry is not retry-out, and verify is executed again after changing the verify condition and returning to step S3.
Step S9: This procedure is the case where the verify retry succeeds, and by learning the regeneration power and the regeneration magnetic field which are regeneration conditions of the last verify retry process, default or previous regeneration conditions are changed to the optimized conditions determined by the learning.
Step S10: This procedure is the case where the write retry succeeds, and by learning the write power which is regeneration condition of the last write retry process, the default or previous regeneration condition is changed to the optimized condition determined by the learning.
Step S11: This procedure is the case where the write retry is not retry-out, and the process is executed again from the erase after changing the write condition and returning to step S1.
In details of the read leaning process in step S9 of FIG. 2, although the timing is different, the process procedures are the same as the flowchart of the read command process of FIGS. 1A and 1B. In other words, in the read learning process with the write verify, when multiple sectors are processed by a write command and completed normally, a retry setting is learned at the time of termination to change default conditions. In this case, a target of the learning is a retry setting when the last sector is processed. In other words, the read learning is performed when the write command process is completed; a counter is controlled by the last successful mode; the regeneration power and the regeneration magnetic field are learned; and regeneration conditions for the write verify are optimized.
FIG. 3 is a flowchart of the write learning process in step S10 for the write command of FIG. 2 which consists of following process procedures.
Step S1: It is checked whether contents for changing the write power setting of last successful retry mode exist or not and if the contents for changing the setting exist, the process proceeds to step S2, and otherwise, the process is terminated.
Step S2: It is checked whether, at the time of the successful write retry, the write power setting is power up or not. If the setting is power up, the process proceeds to step S3; and otherwise, the process proceeds to step S4.
Step S3: A record power learning counter is updated.
Step S4: It is checked whether, at the time of the successful write retry, the write power setting is power down or not. If the setting is power down, the process proceeds to step S5; and otherwise, the process proceeds to step S6.
Step S5: A record power learning counter is updated.
Step S6: It is checked whether the counter exceeds a threshold or not. If exceeding, the process proceeds to step S7; and otherwise, the process is terminated.
Step S7: By learning the write power which is a write condition of the last write retry process, a default or previous record condition is changed to the optimized condition determined by the learning. For example, if the record condition of the last retry process is to up the power, the default write power is increased by predefined value (see, e.g., Japanese Patent Application Laid-Open Publication No. 2000-182292).
However, in such a conventional optical storage apparatus, when a retry occurs in regeneration and when processes of multiple sectors are normally completed with one (1) read command by implementing predefined staged settings for intensities of a laser beam and a regeneration magnetic field, since a default condition is changed by learning a retry setting at the time of termination, the target of learning will be a retry setting at the time of processing the last sector; therefore, when large majority of sectors are processed by one (1) command, a retry conditions may not necessarily accord with a retry condition when the last sector is processed; and from the point of view of whole sectors, mismatched learning may be performed resulting in a problem. The timing of the learning is the same in the case of recording, and if a retry occurs when multiple sectors are processed by one (1) command, the target of learning will be a record setting and a verify setting at the time of processing the last sector, and therefore, from the point of view of one (1) command, mismatched learning may be performed resulting in a problem.